The present invention relates to a process for simultaneously reading and certifying, using a processing device, information present at an address in a memory of an electronic medium, in particular a removable and portable medium such as a memory card, also called a microprocessor card or a chip card.
The invention is in the field of verification of information recorded in such a memory for the purpose of preventing a fraud from deceitfully intervening in the exchange of information between the memory card and a processing device enabling this card to be processed either locally or remotely.
It is known that for each envisaged application, exchanges of information are carried out between the card and the processing device in order to authorize persons to carry out protected operations.
Most of the applications require, at any particular time, the reading and/or writing of the information in the memory of the card, for example to retain a record of the operation carried out; it is therefore of prime importance to be able to verify with certainty the existence of the information present in the memory of the card; in order to facilitate this check, it is known that the processing device knows at which address, in the memory of the card, the said information is located.
According to patent EP No. 0,096,599 it is necessary that the processing device knows the content of the information to be checked in advance; thus the object of the check is to verify the conformity of the information.
This prior knowledge of the content of the information is a disadvantage when the processing device does not know the information to be read, which is particularly the case when it is not the device which caused the writing of the information.
The object of the present invention is to remove this disadvantage.